Monday, February 19, 2007
I recently finished reading the book pictured at left. It's a book about The Genographic Project being run by National Geographic. The purpose of the project is to show the origins of modern humans and how they all relate to one another. Think of it as a giant family tree for the entire human race.
The project is based on genetics. Every human being carries two sex chromosomes. Women have two X chromosomes and males have an X and a Y. Since the Y chromosome gets passed down from father to son without being recombined as all other genes are, they can be very useful in tracking lineages through the male line. Furthermore, because mutations occur in the Y chromosome at a fairly constant rate, you can estimate, based on how many mutations there are in the gene, how long long it has been since you and any other given person had a common male ancestor. Using this data, scientists have developed a family tree for human beings and have found that all human beings today come from one man who lived in Africa roughly 60,000 - 90,000 years ago. Such a person has been dubbed "Adam" by the project. Of course, it's sixty thousand years and not six thousand, and he wasn't the first or only male... but so be it.
You might think that this research has been poo-pooed by the Jewish establishment, as is pretty much any other idea that contradicts a literal reading of Tanach (the Bible). As it turns out, that's not the case; on the contrary it has been embraced. It was embraced because the same technology was employed to show that the vast majority of the world's Kohanim today carry the mark of being descendants of a single individual who lived about three years ago. This was trumpeted as being a proof to the truth of the Torah -- after all, modern science shows that most of the Kohanim in the world are descended from a single person... just as the Torah says. This scientific achievement is trumpeted on such kiruv sites sites as Aish and Hidabroot.
Of course, I find it interesting how they embrace the technology that shows that today's Kohanim have a single common ancestor 3,000 years ago, but reject that same technology when it shows that people have been around for a lot longer than 6,000 years.
What's interesting about this particular bit of science is that it's immune to the Gosse theory. The Gosse theory is the often-stated idea that the world was created "looking old." The classic example is that on the day Adam was created, he was created as an adult. If he was created as a twenty year old, it would imply that at least twenty years had previously existed.
Gosse's idea can work for most of the proofs to the age of the universe and the earth, but in this case, Gosse falls down flat. The reason is as follows: Genetic testing has shown us all to have a common male ancestor 60,000 years ago (and a common female ancestor much earlier than that). If we all descended from a single male only 6,000 years ago, then there would not be as much genetic variation in the human species as currently exists -- only 10% of the variations in the Y chromosome would exist. The fact that as much variation exists as it does shows that our common ancestor is much further back than 6,000 years (based on the known rate of Y chromosome mutation).
Rabbi Dovid Kornriech wrote in the Yated last year that much of the evidence of an old universe can be thrown into doubt because the laws of nature were different during the six days of creation. By claiming that some or all of nature's laws were different during the six days of creation, he claims that most, if not all of the physical, geological, archaeological and paleontological evidence can be thrown into question or tossed out completely.
However, such a theory cannot really apply to Y chromosome (and mt-DNA studies which show lineages through the female line). Once Adam came into being, creation was complete. If a literal reading of Genesis were true, then the greatest variation in the Y-chromosome we would see would be 6,000 years. The fact that we see ten times that difference clearly shows that since Adam, there have been well more than 6,000 years. It would be highly dubious to state that the rate of genetic mutation changed somewhere along the way *since* creation. It would almost be like saying that the moon changed from a gas to a solid since the Rambam's time.